TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCT OBER 2002
D
150 mW Stereo Output
D
PC Power Supply Compatible
– Fully Specified for 3.3 V and 5 V
Operation
– Operation to 2.5 V
D
Pop Reduction Circuitry
D
Internal Midrail Generation
D
Thermal and Short-Circuit Protection
D
Surface-Mount Packaging
BYPASS
D OR DGN PACKAGE
(TOP VIEW)
VO1
IN–
GND
1
2
3
4
8
7
6
5
V
DD
VO2
IN2–
SHUTDOWN
– PowerPAD MSOP
– SOIC
D
Pin Compatible With LM4880 and LM4881
(SOIC)
description
The TP A122 is a stereo audio power amplifier packaged in either an 8-pin SOIC, or an 8-pin PowerPADMSOP
package capable of delivering 150 mW of continuous RMS power per channel into 8-Ω loads. Amplifier gain
is externally configured by means of two resistors per input channel and does not require external compensation
for settings of 1 to 10.
THD+N when driving an 8-Ω load from 5 V is 0.1% at 1 kHz, and less than 2% across the audio band of 20 Hz
to 20 kHz. For 32-Ω loads, the THD+N is reduced to less than 0.06% at 1 kHz, and is less than 1% across the
audio band of 20 Hz to 20 kHz. For 10-kΩ loads, the THD+N performance is 0.01% at 1 kHz, and less than 0.02%
across the audio band of 20 Hz to 20 kHz.
typical application circuit
Audio
Input
Audio
Input
From Shutdown
Control Circuit
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
R
I
C
I
C
B
R
I
C
I
R
F
R
F
2
3
6
5
320 kΩ 320 kΩ
IN1–
BYPASS
IN2–
SHUTDOWN
VDD/2
–
+
–
+
Bias
Control
V
DD
VO1
VO2
8
1
C
7
C
4
V
DD
C
S
C
C
PowerPAD is a trademark of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Copyright 2002, Texas Instruments Incorporated
1
TPA122
MSOP
I/O
DESCRIPTION
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
AVAILABLE OPTIONS
PACKAGED DEVICES
T
A
–40°C to 85°C TPA122D TPA122DGN TI AAE
†
The D and DGN package is available in left-ended tape and reel only (e.g., TPA122DR,
TPA122DGNR).
SMALL OUTLINE
(D)
†
Terminal Functions
TERMINAL
NAME NO.
BYPASS 3 I Tap to voltage divider for internal mid-supply bias supply. Connect to a 0.1 µF to 1 µF low ESR capacitor for
GND 4 I GND is the ground connection.
IN1– 2 I IN1– is the inverting input for channel 1.
IN2– 6 I IN2– is the inverting input for channel 2.
SHUTDOWN 5 I Puts the device in a low quiescent current mode when held high
V
DD
VO1 1 O VO1 is the audio output for channel 1.
VO2 7 O VO2 is the audio output for channel 2.
8 I VDD is the supply voltage terminal.
best performance.
MSOP
(DGN)
†
Symbolization
absolute maximum ratings over operating free-air temperature (unless otherwise noted)
†
Supply voltage, VDD 6 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage, V
–0.3 V to VDD + 0.3 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I
Continuous total power dissipation internally limited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating junction temperature range, T
Storage temperature range, T
–65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stg
–40°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
J
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds 260°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
†
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
DISSIPATION RATING TABLE
PACKAGE
D 725 mW 5.8 mW/°C 464 mW 377 mW
DGN 2.14 W
‡
Please see the Texas Instruments document, PowerPAD Thermally Enhanced Package Application Report
(SLMA002), for more information on the PowerPAD package. The thermal data was measured on a PCB
layout based on the information in the section entitled T exas Instruments Recommended Board for PowerPAD
on page 33 of that document.
TA ≤ 25°C
POWER RATING
‡
DERATING FACTOR
ABOVE TA = 25°C
17.1 mW/°C 1.37 W 1.11 W
TA = 70°C
POWER RATING
POWER RATING
TA = 85°C
recommended operating conditions
MIN MAX UNIT
Supply voltage, V
Operating free-air temperature, T
High-level input voltage, VIH (SHUTDOWN) 0.80 × V
Low-level input voltage, VIL (SHUTDOWN) 0.40 × V
DD
A
2.5 5.5 V
–40 85 °C
DD
DD
V
V
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
dc electrical characteristics at TA = 25°C, VDD = 3.3 V (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
V
OO
PSRR Power supply rejection ratio VDD = 3.2 V to 3.4 V 83 dB
I
DD
I
DD(SD)
Z
I
ac operating characteristics, VDD= 3.3 V, TA = 25°C, RL = 8 Ω
P
O
THD+N Total harmonic distortion + noise PO = 70 mW, 20–20 kHz 2%
B
OM
SNR Signal-to-noise ratio PO = 100 mW 100 dB
V
n
†
Measured at 1 kHz
Output offset voltage 10 mV
Supply current VDD = 2.5, SHUTDOWN = 0 V 1.5 3 mA
Supply current in SHUTDOWN mode VDD = 2.5, SHUTDOWN = V
Input impedance >1 MΩ
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Output power (each channel) THD ≤ 0.1% 70
Maximum output power BW G = 10, THD <5% >20 kHz
Phase margin Open loop 58°
Supply ripple rejection f = 1 kHz 68 dB
Channel/channel output separation f = 1 kHz 86 dB
Noise output voltage 9.5 µV(rms)
DD
10 50 µA
†
mW
dc electrical characteristics at TA = 25°C, VDD = 5.5 V (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
V
OO
PSRR Power supply rejection ratio VDD = 4.9 V to 5.1 V 76 dB
I
DD
I
DD(SD)
|IIH| High-level input current (SHUTDOWN) VDD = 5.5 V, VI = V
|IIL| Low-level input current (SHUTDOWN) VDD = 5.5 V, VI = 0 V 1 µA
Z
I
Output offset voltage 10 mV
Supply current SHUTDOWN = 0 V 1.5 3 mA
Supply current in SHUTDOWN mode SHUTDOWN = V
Input impedance >1 MΩ
DD
DD
60 100 µA
1 µA
ac operating characteristics, VDD=5 V, TA = 25°C, RL = 8 Ω
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
P
O
THD+N Total harmonic distortion + noise PO = 150 mW, 20–20 kHz 2%
B
OM
SNR Signal-to-noise ratio PO = 150 mW 100 dB
V
n
†
Measured at 1 kHz
Output power (each channel) THD ≤ 0.1% 70† mW
Maximum output power BW G = 10, THD <5% >20 kHz
Phase margin Open loop 56°
Supply ripple rejection ratio f = 1 kHz 68 dB
Channel/channel output separation f = 1 kHz 86 dB
Noise output voltage 9.5 µV(rms)
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
3
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
ac operating characteristics, VDD= 3.3 V, TA = 25°C, RL = 32 Ω
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
P
O
THD+N Total harmonic distortion + noise PO = 30 mW, 20–20 kHz 0.5%
B
OM
SNR Signal-to-noise ratio PO = 100 mW 100 dB
V
n
†
Measured at 1 kHz
Output power (each channel) THD ≤ 0.1% 40
Maximum output power BW G = 10, THD <2% >20 kHz
Phase margin Open loop 58°
Supply ripple rejection f = 1 kHz 68 dB
Channel/channel output separation f = 1 kHz 86 dB
Noise output voltage 9.5 µV(rms)
ac operating characteristics, VDD=5 V, TA = 25°C, RL = 32 Ω
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
P
O
THD+N Total harmonic distortion + noise PO = 60 mW, 20–20 kHz 0.4%
B
OM
SNR Signal-to-noise ratio PO = 150 mW 100 dB
V
n
†
Measured at 1 kHz
Output power (each channel) THD ≤ 0.1% 40† mW
Maximum output power BW G = 10, THD <2% >20 kHz
Phase margin Open loop 56°
Supply ripple rejection f = 1 kHz 68 dB
Channel/channel output separation f = 1 kHz 86 dB
Noise output voltage 9.5 µV(rms)
†
mW
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
TYPICAL CHARACTERISTICS
Table of Graphs
FIGURE
1, 2, 4, 5, 7, 8,
vs Frequency
THD+N Total harmonic distortion plus noise
vs Power output
Supply ripple rejection vs Frequency 19, 20
V
n
I
DD
SNR Signal-to-noise ratio vs Voltage gain 35
Output noise voltage vs Frequency 21, 22
Crosstalk vs Frequency
Mute attenuation vs Frequency 27, 28
Open-loop gain and phase margin vs Frequency 29, 30
Output power vs Load resistance 31, 32
Phase vs Frequency 39–44
Supply current vs Supply voltage 33
Closed-loop gain vs Frequency 39–44
Power dissipation/amplifier vs Output power 45, 46
10, 11, 13, 14,
16, 17, 34, 36
3, 6, 9,
12, 15, 18
23–26,
37, 38
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
5
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
TYPICAL CHARACTERISTICS
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
10
VDD = 3.3 V
PO = 30 mW
CB = 1 µ F
RL = 32 Ω
THD+N –Total Harmonic Distortion + Noise – %
1
AV = –10 V/V
0.1
0.01
0.001
20 100 1k 10k 20k
AV = –5 V/V
f – Frequency – Hz
Figure 1
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
OUTPUT POWER
10
VDD = 3.3 V
RL = 32 Ω
AV = –1 V/V
CB = 1 µF
1
10 kHz
AV = –1 V/V
20 kHz
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
10
VDD = 3.3 V
AV = –1 V/V
RL = 32 Ω
CB = 1 µ F
1
PO = 15 mW
PO = 10 mW
PO = 30 mW
f – Frequency – Hz
THD+N –Total Harmonic Distortion + Noise – %
0.1
0.01
0.001
20 100 1k 10k 20k
Figure 2
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
10
VDD = 5 V
PO = 60 mW
RL = 32 Ω
CB = 1 µF
1
AV = –10 V/V
0.1
THD+N –Total Harmonic Distortion + Noise – %
0.1
20 Hz
0.01
11050
PO – Output Power – mW
1 kHz
THD+N –Total Harmonic Distortion + Noise – %
0.01
0.001
20 100 1k 10k 20k
Figure 3
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
AV = –5 V/V
AV = –1 V/V
f – Frequency – Hz
Figure 4
150-mW STEREO AUDIO POWER AMPLIFIER
TYPICAL CHARACTERISTICS
TPA122
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
10
VDD = 5 V
RL = 32 Ω
AV = –1 V/V
CB = 1 µF
1
PO = 30 mW
PO = 15 mW
PO = 60 mW
f – Frequency – Hz
THD+N –Total Harmonic Distortion + Noise – %
0.1
0.01
0.001
20 100 1k 10k 20k
Figure 5
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
10
VDD = 3.3 V
RL = 10 kΩ
PO = 100 µF
CB = 1 µF
1
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
OUTPUT POWER
10
VDD = 5 V
AV = –1 V/V
RL = 32 Ω
CB = 1 µF
20 kHz
1
10 kHz
0.1
20 Hz
THD+N –Total Harmonic Distortion + Noise – %
0.01
0.002 0.01 0.1 0.2
PO – Output Power – W
1 kHz
Figure 6
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
10
VDD = 3.3 V
RL = 10 kΩ
AV = –1 V/V
CB = 1 µF
1
THD+N –Total Harmonic Distortion + Noise – %
0.1
AV = –5 V/V
0.01
AV = –2 V/V
0.001
20 100 1k 10k 20k
f – Frequency – Hz
Figure 7
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
THD+N –Total Harmonic Distortion + Noise – %
0.1
PO = 45 µW
0.01
PO = 130 µW
0.001
20 100 1k 10k 20k
f – Frequency – Hz
PO = 90 µW
Figure 8
7
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
TYPICAL CHARACTERISTICS
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
OUTPUT POWER
10
VDD = 3.3 V
RL = 10 kΩ
AV = –1 V/V
CB = 1 µF
1
THD+N –Total Harmonic Distortion + Noise – %
0.1
0.01
0.001
5 10 100 200
PO – Output Power – µW
20 Hz
20 Hz
1 kHz
Figure 9
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
10
VDD = 5 V
RL = 10 kΩ
AV = –1 V/V
CB = 1 µF
1
10 kHz
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
10
VDD = 5 V
RL = 10 kΩ
PO = 300 µW
CB = 1 µF
1
THD+N –Total Harmonic Distortion + Noise – %
0.1
AV = –1 V/V
0.01
0.001
20 100 1k 10k 20k
f – Frequency – Hz
AV = –5 V/V
AV = –2 V/V
Figure 10
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
OUTPUT POWER
10
VDD = 5 V
RL = 10 kΩ
AV = –1 V/V
CB = 1 µ F
1
0.1
0.01
PO = 100 µW
THD+N –Total Harmonic Distortion + Noise – %
0.001
20 100 1k 10k 20k
8
PO = 300 µW
f – Frequency – Hz
Figure 11
THD+N –Total Harmonic Distortion + Noise – %
0.1
0.01
0.001
5 10 100 500
PO = 200 µW
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
20 kHz
20 Hz
10 kHz
PO – Output Power – µW
Figure 12
1 kHz
150-mW STEREO AUDIO POWER AMPLIFIER
TYPICAL CHARACTERISTICS
TPA122
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
AV = –5 V/V
AV = –2 V/V
100 1k 10k 20k
f – Frequency – Hz
THD+N – Total Harmonic Distortion Plus Noise – %
0.001
0.1
0.01
2
1
20
VDD = 3.3 V
PO = 75 mW
RL = 8 Ω
CB = 1 µF
Figure 13
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
OUTPUT POWER
10
VDD = 3.3 V
RL = 8 Ω
AV = –1 V/V
1
20 kHz
10 kHz
AV = –1 V/V
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
10
VDD = 3.3 V
RL = 8 Ω
AV = –1 V/V
PO = 30 mW
PO = 75 mW
f – Frequency – Hz
THD+N –Total Harmonic Distortion + Noise – %
1
PO = 15 mW
0.1
0.01
0.001
20 100 1k 10k 20k
Figure 14
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
AV = –2 V/V
AV = –5 V/V
0.1
2
1
VDD = 5 V
PO = 100 mW
RL = 8 Ω
CB = 1 µF
1 kHz
0.1
20 Hz
THD+N –Total Harmonic Distortion + Noise – %
0.01
10m 0.1 0.3
PO – Output Power – W
Figure 15
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
THD+N – Total Harmonic Distortion Plus Noise – %
0.001
0.01
20
AV = –1 V/V
100 1k 10k 20k
f – Frequency – Hz
Figure 16
9
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
TYPICAL CHARACTERISTICS
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
FREQUENCY
10
VDD = 5 V
RL = 8 Ω
AV = –1 V/V
PO = 30 mW
PO = 10 mW
THD+N –Total Harmonic Distortion + Noise – %
1
0.1
PO = 60 mW
0.01
0.001
20 100 1k 10k 20k
f – Frequency – Hz
Figure 17
SUPPLY RIPPLE REJECTION RATIO
vs
FREQUENCY
0
–10
VDD = 3.3 V
RL = 8 Ω to 10 kΩ
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
POWER OUTPUT
10
VDD = 5 V
RL = 8 Ω
AV = –1 V/V
20 kHz
1
10 kHz
0.1
20 Hz
THD+N –Total Harmonic Distortion + Noise – %
0.01
10m 0.1 1
PO – Output Power – W
1 kHz
Figure 18
SUPPLY RIPPLE REJECTION RATIO
vs
FREQUENCY
0
–10
VDD = 5 V
RL = 8 Ω to 10 kΩ
–20
–30
–40
–50
–60
CB = 2 µF
–70
Bypass = 1.65 V
Supply Ripple Rejection Ratio – dB
–80
–90
–100
20 100 20k
CB = 0.1 µF
CB = 1 µF
1k
f – Frequency – Hz
Figure 19
10k
–20
–30
–40
–50
–60
CB = 2 µF
–70
–80
Supply Ripple Rejection Ratio – dB
–90
–100
20 100 20k
CB = 0.1 µF
CB = 1 µF
Bypass = 2.5 V
1k
f – Frequency – Hz
Figure 20
10k
10
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
150-mW STEREO AUDIO POWER AMPLIFIER
TYPICAL CHARACTERISTICS
TPA122
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
OUTPUT NOISE VOLTAGE
vs
FREQUENCY
20
10
– Output Noise Voltage – VµV
n
VDD = 3.3 V
BW = 10 Hz to 22 kHz
AV = –1 V/V
RL = 8 Ω to 10 kΩ
1
20 100 1k 10k 20k
f – Frequency – Hz
Figure 21
CROSSTALK
vs
FREQUENCY
–60
PO = 25 mW
–65
VDD = 3.3 V
RL = 32 Ω
–70
CB = 1 µF
AV = –1 V/V
–75
OUTPUT NOISE VOLTAGE
vs
FREQUENCY
20
10
– Output Noise Voltage – VµV
n
VDD = 5 V
BW = 10 Hz to 22 kHz
RL = 8 Ω to 10 kΩ
AV = –1 V/V
1
20 100 1k 10k 20k
f – Frequency – Hz
Figure 22
CROSSTALK
vs
FREQUENCY
–50
–55
–60
–65
PO = 100 mW
VDD = 3.3 V
RL = 8 Ω
CB = 1 µF
AV = –1 V/V
–80
–85
–90
Crosstalk – dB
–95
–100
–105
–110
20 100 20k
f – Frequency – Hz
IN 2 TO OUT 1
IN 1 TO OUT 2
1k
Figure 23
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
10k
Crosstalk – dB
–70
–75
–80
–85
–90
–95
–100
20 100 20k
f – Frequency – Hz
IN 2 TO OUT 1
IN 1 TO OUT 2
1k
Figure 24
10k
11
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
TYPICAL CHARACTERISTICS
CROSSTALK
vs
FREQUENCY
–60
–65
–65
–75
–80
–85
–90
Crosstalk – dB
–95
–100
–105
–110
20 100 10k
f – Frequency – Hz
VDD = 5 V
PO = 25 mW
CB = 1 µF
RL = 32 Ω
AV = –1 V/V
IN 2 TO OUT 1
IN 1 TO OUT 2
1k
Figure 25
MUTE ATTENUATION
vs
FREQUENCY
0
VDD = 3.3 V
RL = 32 Ω
CB = 1 µF
20 100 20k
f – Frequency – Hz
1k
Mute Attenuation – dB
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
Figure 27
10k
20k
CROSSTALK
vs
FREQUENCY
–50
VDD = 5 V
–55
PO = 100 mW
CB = 1 µF
–60
RL = 8 Ω
AV = –1 V/V
–65
–70
–75
–80
Crosstalk – dB
–85
–90
–95
–100
20 100 10k
f – Frequency – Hz
IN 2 TO OUT 1
IN 1 TO OUT 2
1k
Figure 26
MUTE ATTENUATION
vs
FREQUENCY
0
VDD = 5 V
–10
CB = 1 µF
RL = 32 Ω
–20
–30
–40
–50
–60
–70
Mute Attenuation – dB
–80
–90
–100
20 100 10k
f – Frequency – Hz
1k
Figure 28
20k
20k
12
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
150-mW STEREO AUDIO POWER AMPLIFIER
TYPICAL CHARACTERISTICS
OPEN-LOOP GAIN AND PHASE MARGIN
vs
FREQUENCY
100
VDD = 3.3 V
TA = 25°C
80
No Load
TPA122
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
150°
120°
Open-Loop Gain – dB
60
40
Gain
20
0
–20
100 10k
1k 100k 10M10
f – Frequency – Hz
Figure 29
OPEN-LOOP GAIN AND PHASE MARGIN
vs
FREQUENCY
100
80
Phase
VDD = 5 V
TA = 25°C
No Load
90°
60°
30°
0°
–30°
150°
120°
m
φ – Phase Margin
60
40
Gain
20
Open-Loop Gain – dB
0
–20
100 1k 10k 10M1M100k
f – Frequency – Hz
Figure 30
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Phase
90°
60°
30°
φ – Phase Margin
0°
–30°
m
13
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
TYPICAL CHARACTERISTICS
120
100
– Output Power – mW
O
P
80
60
40
20
0
1.4
1.2
8
16 32
OUTPUT POWER
vs
LOAD RESISTANCE
THD+N = 1 %
VDD = 3.3 V
AV = –1 V/V
24 40 64
RL – Load Resistance – Ω
48 56
Figure 31
SUPPLY CURRENT
vs
SUPPLY VOLTAGE
OUTPUT POWER
vs
LOAD RESISTANCE
300
THD+N = 1 %
VDD = 5 V
250
200
150
100
– Output Power – mW
O
P
50
0
8
24 40 64
16 32
RL – Load Resistance – Ω
AV = –1 V/V
48 56
Figure 32
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
1
VI = 1 V
AV = –1 V/V
RL = 10 kΩ
CB = 1 µF
FREQUENCY
14
– Supply Current – mA
DD
I
0.8
0.6
0.4
0.2
1
0
2.5
34
3.5 4.5
VDD – Supply Voltage – V
5 5.5
Figure 33
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
THD+N – Total Harmonic Distortion Plus Noise – %
0.001
0.1
0.01
20
100 1k 10k 20k
f – Frequency – Hz
Figure 34
150-mW STEREO AUDIO POWER AMPLIFIER
TYPICAL CHARACTERISTICS
TPA122
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
SNR – Signal-to-Noise Ratio – dB
104
102
100
–60
–70
–80
–90
98
96
94
92
VI = 1 V
1
VDD = 3.3 V
VO = 1 V
RL = 10 kΩ
CB = 1 µF
SIGNAL-TO-NOISE RATIO
vs
VOLTAGE GAIN
57910
AV – Voltage Gain – V/V
Figure 35
CROSSTALK
vs
FREQUENCY
TOTAL HARMONIC DISTORTION PLUS NOISE
vs
1
VDD = 5 V
AV = –1 V/V
RL = 10 kΩ
CB = 1 µF
0.1
0.01
THD+N – Total Harmonic Distortion Plus Noise – %
86243
0.001
20
FREQUENCY
100 1k 10k 20k
f – Frequency – Hz
Figure 36
CROSSTALK
vs
–60
–70
–80
–90
VDD = 5 V
VO = 1 V
RL = 10 kΩ
CB = 1 µF
FREQUENCY
Crosstalk – dB
–100
–110
–120
–130
–140
–150
20
IN2 to OUT1
IN1 to OUT2
100 1k 10k 20k
f – Frequency – Hz
Figure 37
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Crosstalk – dB
–100
–110
–120
–130
–140
–150
20
IN2 to OUT1
IN1 to OUT2
100 1k 10k 20k
f – Frequency – Hz
Figure 38
15
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
TYPICAL CHARACTERISTICS
CLOSED-LOOP GAIN AND PHASE
FREQUENCY
vs
200°
Closed-Loop Gain – dB
30
20
–10
30
20
10
Phase
VDD = 3.3 V
RI = 20 kΩ
RF = 20 kΩ
RL = 32 Ω
CI = 1 µF
AV = –1 V/V
Gain
0
10
100 1k 10k 1M
f – Frequency – Hz
100k
180°
160°
140°
Phase
120°
100°
80°
Figure 39
CLOSED-LOOP GAIN AND PHASE
vs
FREQUENCY
Phase
VDD = 5 V
RI = 20 kΩ
RF = 20 kΩ
RL = 32 Ω
CI = 1 µF
AV = –1 V/V
200°
180°
160°
140°
120°
100°
80°
Phase
16
Closed-Loop Gain – dB
–10
10
0
10
100 1k 10k 1M
Gain
f – Frequency – Hz
Figure 40
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
100k
40
20
150-mW STEREO AUDIO POWER AMPLIFIER
TYPICAL CHARACTERISTICS
CLOSED-LOOP GAIN AND PHASE
vs
FREQUENCY
Phase
VDD = 3.3 V
RI = 20 kΩ
RF = 20 kΩ
RL = 8 Ω
CI = 1 µF
AV = –1 V/V
Gain
0
TPA122
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
200°
180°
160°
140°
120°
100°
80°
60°
Phase
Closed-Loop Gain – dB
Closed-Loop Gain – dB
–20
30
20
10
–10
10
100 1k 10k 1M
f – Frequency – Hz
100k
Figure 41
CLOSED-LOOP GAIN AND PHASE
vs
FREQUENCY
Phase
VDD = 3.3 V
RI = 20 kΩ
RF = 20 kΩ
RL = 10 kΩ
CI = 1 µF
AV = –1 V/V
0
10
100 1k 10k 1M
Gain
100k
f – Frequency – Hz
200°
180°
160°
140°
120°
100°
80°
Phase
Figure 42
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
17
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
TYPICAL CHARACTERISTICS
CLOSED-LOOP GAIN AND PHASE
FREQUENCY
VDD = 5 V
RI = 20 kΩ
RF = 20 kΩ
RL = 8 Ω
CI = 1 µF
AV = –1 V/V
20
0
vs
Phase
Gain
200°
180°
160°
140°
120°
100°
80°
60°
40°
Phase
Closed-Loop Gain – dB
Closed-Loop Gain – dB
–20
30
20
–10
10
10
100 1k 10k 1M
f – Frequency – Hz
100k
Figure 43
CLOSED-LOOP GAIN AND PHASE
vs
FREQUENCY
Phase
VDD = 5 V
RI = 20 kΩ
RF = 20 kΩ
RL = 10 kΩ
CI = 1 µF
AV = –1 V/V
Gain
0
10
100 1k 10k 1M
f – Frequency – Hz
100k
200°
180°
160°
140°
120°
100°
80°
Phase
18
Figure 44
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
150-mW STEREO AUDIO POWER AMPLIFIER
TYPICAL CHARACTERISTICS
TPA122
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
Amplifier Power – mW
80
70
60
50
40
30
20
10
0
0
POWER DISSIPATION/AMPLIFIER
vs
OUTPUT POWER
VDD = 3.3 V
16 Ω
32 Ω
64 Ω
8 Ω
80 120 180 200
Load Power – mW
14010020 6040
Figure 45
160
Amplifier Power – mW
180
160
140
120
100
80
60
40
20
0
0
POWER DISSIPATION/AMPLIFIER
vs
OUTPUT POWER
VDD = 5 V
64 Ω
8 Ω
16 Ω
32 Ω
80 120 180 200
Load Power – mW
14010020 6040
Figure 46
160
APPLICATION INFORMATION
ǒ
R
F
R
and R
F
Ǔ
I
I
and RI according to equation 1.
F
increases. In
values is required for proper start-up operation of the amplifier. Taken together
F
R
FRI
+
RF)
R
I
F
gain setting resistors, R
The gain for the TPA122 is set by resistors R
Gain
+*
Given that the TPA122 is a MOS amplifier, the input impedance is very high. Consequently input leakage
currents are not generally a concern, although noise in the circuit increases as the value of R
addition, a certain range of R
it is recommended that the effective impedance seen by the inverting node of the amplifier be set between
5 kΩ and 20 kΩ. The effective impedance is calculated in equation 2.
Effective Impedance
As an example, consider an input resistance of 20 kΩ and a feedback resistor of 20 kΩ. The gain of the amplifier
would be –1 and the effective impedance at the inverting terminal would be 10 kΩ, which is within the
recommended range.
(1)
(2)
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
19
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
APPLICATION INFORMATION
gain setting resistors, R
and RI (continued)
F
For high performance applications, metal film resistors are recommended because they tend to have lower
noise levels than carbon resistors. For values of R
to a pole formed from R
and the inherent input capacitance of the MOS input structure. For this reason, a small
F
compensation capacitor of approximately 5 pF should be placed in parallel with R
above 50 kΩ, the amplifier tends to become unstable due
F
. This, in effect, creates a
F
low-pass filter network with the cutoff frequency defined in equation 3.
f
c(lowpass)
+
For example, if RF is 100 kΩ and CF is 5 pF then f
input capacitor, C
I
In the typical application, an input capacitor, C
proper dc level for optimum operation. In this case, C
2pR
1
C
F
F
c(lowpass)
, is required to allow the amplifier to bias the input signal to the
I
is 318 kHz, which is well outside the audio range.
and RI form a high-pass filter with the corner frequency
I
determined in equation 4.
f
c(highpass)
+
2pR
1
C
I
I
The value of CI is important to consider, as it directly af fects the bass (low frequency) performance of the circuit.
Consider the example where R
is 20 kΩ and the specification calls for a flat bass response down to 20 Hz.
I
Equation 4 is reconfigured as equation 5.
C
+
I
2pR
1
f
c(highpass)
I
(3)
(4)
(5)
In this example, CI is 0.40 µF, so one would likely choose a value in the range of 0.47 µF to 1 µF. A further
consideration for this capacitor is the leakage path from the input source through the input network (R
the feedback resistor (R
) to the load. This leakage current creates a dc offset voltage at the input to the amplifier
F
that reduces useful headroom, especially in high-gain applications (> 10). For this reason a low-leakage
tantalum or ceramic capacitor is the best choice. When polarized capacitors are used, the positive side of the
capacitor should face the amplifier input in most applications, as the dc level there is held at V
DD
likely higher than the source dc level. Please note that it is important to confirm the capacitor polarity in the
application.
power supply decoupling, C
S
The TP A122 is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to
ensure that the output total harmonic distortion (THD) is as low as possible. Power supply decoupling also
prevents oscillations for long lead lengths between the amplifier and the speaker. The optimum decoupling is
achieved by using two capacitors of different types that target different types of noise on the power supply leads.
For higher frequency transients, spikes, or digital hash on the line, a good low equivalent-series-resistance
(ESR) ceramic capacitor, typically 0.1 µF, placed as close as possible to the device V
lead, works best. For
DD
filtering lower-frequency noise signals, a larger aluminum electrolytic capacitor of 10 µF or greater placed near
the power amplifier is recommended.
, CI) and
I
/2, which is
20
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
150-mW STEREO AUDIO POWER AMPLIFIER
APPLICATION INFORMATION
TPA122
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
midrail bypass capacitor, C
The midrail bypass capacitor, C
at which the amplifier starts up. This helps to push the start-up pop noise into the subaudible range (so low it
can not be heard). The second function is to reduce noise produced by the power supply caused by coupling
into the output drive signal. This noise is from the midrail generation circuit internal to the amplifier. The capacitor
is fed from a 160-kΩ source inside the amplifier. To keep the start-up pop as low as possible, the relationship
shown in equation 6 should be maintained.
1
ǒ
CB
160 kΩ
As an example, consider a circuit where CB is 1 µF, CI is 1 µF, and RI is 20 kΩ. Inserting these values into the
equation 9 results in: 6.25 ≤ 50 which satisfies the rule. Bypass capacitor, C
or tantalum low-ESR capacitors are recommended for the best THD and noise performance.
output coupling capacitor, C
In the typical single-supply single-ended (SE) configuration, an output coupling capacitor (C
block the dc bias at the output of the amplifier, thus preventing dc currents in the load. As with the input coupling
capacitor, the output coupling capacitor and impedance of the load form a high-pass filter governed by
equation 7.
2pR
1
C
L
f
+
c
B
, serves several important functions. During start-up, CB determines the rate
B
1
v
Ǔ
ǒ
Ǔ
CIR
I
, values of 0.1 µF to 1 µF ceramic
B
C
) is required to
C
C
(6)
(7)
The main disadvantage, from a performance standpoint, is that the typically small load impedances drive the
low-frequency corner higher. Large values of C
the example where a C
frequency response characteristics of each configuration.
Table 1. Common Load Impedances vs Low Frequency Output Characteristics in SE Mode
As Table 1 indicates, headphone response is adequate and drive into line level inputs (a home stereo for
example) is very good.
The output coupling capacitor required in single-supply SE mode also places additional constraints on the
selection of other components in the amplifier circuit. With the rules described earlier still valid, add the following
relationship:
1
ǒ
CB
160 kΩ
of 68 µF is chosen and loads vary from 32 Ω to 47 kΩ. Table 1 summarizes the
C
R
L
32 Ω 68 µF
10,000 Ω 68 µF 0.23 Hz
47,000 Ω 68 µF 0.05 Hz
1
v
Ǔ
ǒ
Ǔ
CIR
I
Ơ
1
RLC
C
are required to pass low frequencies into the load. Consider
C
C
C
LOWEST FREQUENCY
73 Hz
(8)
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
21
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
APPLICATION INFORMATION
using low-ESR capacitors
Low-ESR capacitors are recommended throughout this application. A real capacitor can be modeled simply as
a resistor in series with an ideal capacitor. The voltage drop across this resistor minimizes the beneficial ef fects
of the capacitor in the circuit. The lower the equivalent value of this resistance, the more the real capacitor
behaves like an ideal capacitor.
5-V versus 3.3-V operation
The TPA122 was designed for operation over a supply range of 2.7 V to 5.5 V. This data sheet provides full
specifications for 5-V and 3.3-V operation since these are considered to be the two most common standard
voltages. There are no special considerations for 3.3-V versus 5-V operation as far as supply bypassing, gain
setting, or stability. Supply current is slightly reduced from 3.5 mA (typical) to 2.5 mA (typical). The most
important consideration is that of output power. Each amplifier in the TPA122 can produce a maximum voltage
swing ofV
when V
power into the load before distortion begins to become significant.
– 1 V. This means, for 3.3-V operation, clipping starts to occur when V
DD
= 4 V while operating at 5 V . The reduced voltage swing subsequently reduces maximum output
O(PP)
= 2.3 V as opposed
O(PP)
22
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
MECHANICAL DATA
D (R-PDSO-G**) PLASTIC SMALL-OUTLINE PACKAGE
14 PINS SHOWN
0.050 (1,27)
14
1
0.069 (1,75) MAX
0.020 (0,51)
0.014 (0,35)
8
7
A
0.010 (0,25)
0.004 (0,10)
DIM
0.157 (4,00)
0.150 (3,81)
PINS **
0.010 (0,25)
0.244 (6,20)
0.228 (5,80)
8
M
Seating Plane
0.004 (0,10)
14
0.008 (0,20) NOM
0°–8°
16
Gage Plane
0.010 (0,25)
0.044 (1,12)
0.016 (0,40)
A MAX
A MIN
NOTES: A. All linear dimensions are in inches (millimeters).
B. This drawing is subject to change without notice.
C. Body dimensions do not include mold flash or protrusion, not to exceed 0.006 (0,15).
D. Falls within JEDEC MS-012
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
0.197
(5,00)
0.189
(4,80)
0.344
(8,75)
0.337
(8,55)
0.394
(10,00)
0.386
(9,80)
4040047/D 10/96
23
TPA122
150-mW STEREO AUDIO POWER AMPLIFIER
SLOS211D – AUGUST1998 – REVISED OCTOBER 2002
MECHANICAL DATA
DGN (S-PDSO-G8) PowerPAD PLASTIC SMALL-OUTLINE PACKAGE
0,65
8
1
1,07 MAX
3,05
2,95
0,38
0,25
5
3,05
2,95
4
Seating Plane
0,15
0,05
0,25
4,98
4,78
M
0,10
Thermal Pad
(See Note D)
0,15 NOM
0°–6°
Gage Plane
0,25
0,69
0,41
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C. Body dimensions include mold flash or protrusions.
D. The package thermal performance may be enhanced by attaching an external heat sink to the thermal pad.
This pad is electrically and thermally connected to the backside of the die and possibly selected leads.
E. Falls within JEDEC MO-187
PowerPAD is a trademark of Texas Instruments.
4073271/A 04/98
24
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
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